As the animals in routine use in studies on therapeutic drugs for dermatitis, among other diseases, the mouse, rat, and rabbit can be mentioned. However, there is the disadvantage that in order that those animals may be actually used in such studies, they must be subjected to various pretreatments. In a screening for antiallergic drugs, for instance, animals which have undergone PCA (passive cutaneous anaphylaxis) reaction are used as is well known. However, to induce this PCA reaction in animals, an antiserum containing a homologous or heterologous tissue reagin must be administered to denuded animals and for quantification of this reaction, an antigen and a dye or radiolabeled albumin must be administered intravenously after a certain interval of time (48-168 hours when the homologous PCA IgE antibody was used). (Hiroichi Nagai: 2-1 Dermatitis (1) PCA Reaction, Seibutsu-Yaku-Kagaku Jikken Koza (Biopharmaceutical Science Experiment Series) Vol. 12, Inflammation and Allergy (I-1) (ed. Kazuo Ohuchi), Hirokawa Shoten, Tokyo, 1993, p.96-109). The foregoing means not only the absolute need for such pretreatment procedures but also the risk for the experimenter being exposed to the antiserum and other factors which might adversely affect his or her health. Therefore, development of an animal model of disease, which might be submitted to studies on therapeutic drugs, such as drugs for dermatitis, without said or other pretreatments, has been awaited.
The object of the present invention, therefore, is to provide an animal model of disease meeting the above demand.
During, intensive investigations, the inventors succeeded in producing an atrichia mouse suited for the object. The present invention is based on the above results.